Compared to other imaging modalities such as computed tomography and ultrasound, magnetic resonance imaging (MRI) is relatively more sensitive to motion due to the longer scan time in MRI. One of the major sources of motion is respiration.
Respiratory motion greatly affects MRI imaging of abdominal organs, especially in the presence of blood flow. On the other hand, there is a need to image vascular structures and blood flow or perfusion in the abdominal organs, such as the liver, using MRI because MRI is noninvasive and produces high image quality. For example, in macroscale, angiography is needed to study liver macro vasculature to examine liver transplant patency and portal flow changes during liver fibrosis. As another example, in microscale, microvasculature, such as perfusion, is needed to evaluate liver cancers and early response to anti-angiogenic agents.
Unfortunately, respiratory motion can be quite extensive in the abdomen. In addition, motion effects are often exacerbated in patients with diseases that alter their respiratory breathing pattern or that limit the patient's ability to hold their breath. Of course, patients with such limiting pathologies are often a large portion of the population that benefits from such imaging.
It would therefore be highly desirable to provide a method for generating MRI images that are less sensitive to motion.